Massive transfusion of low-titer cold-stored O-positive whole blood in a civilian trauma setting

The effects of plasma to red blood cells transfusion ratio on in-hospital mortality in patients with acute type A aortic dissection

Background

Blood transfusion is a frequent and necessary practice in acute type A aortic dissection (AAAD) patients, but the effect of plasma/red blood cells (RBCs) ratio on mortality remains unclear. The aim of this study is to investigate the association between plasma/RBCs transfusion ratio and in-hospital mortality in patients with AAAD.

Methods

Patients were admitted to Xiangya Hospital of Central South University from January 1, 2016 to December 31, 2021. Clinical parameters were recorded. Multivariate Cox regression model was used to analyze the association between transfusion and in-hospital mortality. We used the smooth curve fitting and segmented regression model to assess the threshold effect between plasma/RBCs transfusion ratio and in-hospital mortality in patients with AAAD.

Results

The volumes of RBCs [14.00 (10.12-20.50) unit] and plasma [19.25 (14.72-28.15) unit] transfused in non-survivors were significantly higher than in survivors [RBCs: 8.00 (5.50-12.00) unit]; plasma: [10.35 (6.50-15.22) unit]. Multivariate Cox regression analysis showed plasma transfusion was an independent risk factor of in-hospital mortality. Adjusted HR was 1.03 (95% CI: 0.96-1.11) for RBCs transfusion and 1.08 (95% CI: 1.03-1.13) for plasma transfusion. In the spline smoothing plot, mortality risk increased with plasma/RBCs transfusion ratio leveling up to the turning point 1. Optimal plasma/RBCs transfusion ratio with least mortality risk was 1. When the plasma/RBCs ratio was <1 (adjusted HR per 0.1 ratio: 0.28, 95% CI per 0.1 ratio: 0.17-0.45), mortality risk decreased with the increase of ratio. When the plasma/RBCs ratio was 1-1.5 (adjusted HR per 0.1 ratio: 2.73, 95% CI per 0.1 ratio:1.13-6.62), mortality risk increased rapidly with the increase of ratio. When the plasma/RBCs ratio was >1.5 (adjusted HR per 0.1 ratio: 1.09, 95% CI per 0.1 ratio:0.97-1.23), mortality risk tended to reach saturation, and increased non-significantly with the increase of ratio.

Conclusion

A 1:1 plasma/RBCs ratio was associated with the lowest mortality in the patients with AAAD. And non-linear relationship existed between plasma/RBCs ratio and mortality.

Back to the Future: Whole Blood Resuscitation of the Severely Injured Trauma Patient

ABSTRACT

Following advances in blood typing and storage, whole blood transfusion became available for the treatment of casualties during World War I. While substantially utilized during World War II and the Korean War, whole blood transfusion declined during the Vietnam War as civilian centers transitioned to blood component therapies. Little evidence supported this shift, and recent conflicts in Iraq and Afghanistan have renewed interest in military and civilian applications of whole blood transfusion. Within the past two decades, civilian trauma centers have begun to study transfusion protocols based upon cold-stored, low anti-A/B titer type O whole blood for the treatment of severely injured civilian trauma patients. Early data suggests equivalent or improved resuscitation and hemostatic markers with whole blood transfusion when compared to balanced blood component therapy. Additional studies are taking place to define the optimal way to utilize low-titer type O whole blood in both prehospital and trauma center resuscitation of bleeding patients.

The rebirth of the cool: a narrative review of the clinical outcomes of cold stored low titer group O whole blood recipients compared to conventional component recipients in trauma

There has been renewed interest in the use of low titer group O whole blood (LTOWB) for the resuscitation of civilian casualties. LTOWB offers several advantages over conventional components such as providing balanced resuscitation in one bag that contains less additive/preservative solution than an equivalent volume of conventional components, is easier and faster to transfuse than multiple components, avoids blood product ratio confusion, contains cold stored platelets, and reduces donor exposures. The resurgence in its use in the resuscitation of civilian trauma patients has led to the publication of an increasing number of studies on its use, primarily amongst adult recipients but also in pediatric patients. These studies have indicated that hemolysis does not occur amongst adult and pediatric non-group O recipients of a modest quantity of LTOWB. The published studies to date on mortality have shown conflicting results with some demonstrating a reduction following LTOWB transfusion while most others have not shown a reduction; there have not been any studies to date that have found significantly increased overall mortality amongst LTOWB recipients. Similarly, when other clinical outcomes, such as venous thromboembolism, sepsis, hospital or intensive care unit lengths of stay are evaluated, LTOWB recipients have not demonstrated worse outcomes compared to conventional component recipients. While definitive proof of the trends in these morbidity and mortality outcomes awaits confirmation in randomized controlled trials, the evidence to date indicates the safety of transfusing LTOWB to injured civilians.

Cold-stored platelets have better preserved contractile function in comparison with room temperature-stored platelets over 21 days

Although it is well established that transfusion of platelets in cases of severe bleeding reduces mortality, the availability of platelets is hampered by harsh restrictions on shelf life due to elevated risks of microbial contamination and functional losses with room temperature-stored platelets (RTP) kept at 22°C. In contrast, many recent studies have shown that 4°C cold-stored platelets (CSP) are able to overcome these shortcomings leading to the recent Food and Drug Administration licensure for 14-day stored CSP when conventional platelets are unavailable. This work expands the evidence supporting superiority of CSP function by assaying the less explored platelet-mediated clot retraction of RTP and CSP in either autologous plasma (AP) or platelet additive solution (PAS) for up to 21 days. The results demonstrate that CSP have better preservation of contractile function, exhibiting retraction for up to 21 days in both AP and PAS and forming highly ordered fibrin scaffolds similar to those of fresh platelets. In contrast, RTP stored in AP showed impaired contractile function by Day 5 with no retraction after 10 days, whereas PAS-stored RTP retained contractile function for up to 21 days. Collectively, these findings support extended storage of CSP and suggest that storage in PAS can mitigate functional losses in RTP.

Coagulation function of never frozen liquid plasma stored for 40 days

BACKGROUND

Never frozen liquid plasma (LP) has limited shelf life versus fresh frozen plasma (FFP) or plasma frozen within 24 h (PF24). Previous studies showed decreasing factor activities after Day (D)14 in thawed FFP but no differences between LP and FFP until D10. This study examined LP function through D40.

STUDY DESIGN AND METHODS

FFP and PF24 were stored at -20°C until assaying. LP was assayed on D5 then stored (4°C) for testing through D40. A clinical coagulation analyzer measured Factor (F)V, FVIII, fibrinogen, prothrombin time (PT), and activated partial thromboplastin time (aPTT). Thromboelastography (TEG) and thrombogram measured functional coagulation. Ristocetin cofactor assay quantified von Willebrand factor (vWF) activity. Residual platelets were counted.

RESULTS

FV/FVIII showed diminished activity over time in LP, while PT and aPTT both increased over time. LP vWF declined significantly by D7. Fibrinogen remained high through D40. Thrombin lagtime was delayed in LP but consistent to D40, while peak thrombin was significantly lower in LP but did not significantly decline over time. TEG R-time and angle remained constant. LP and PF24 (with residual platelets) had initially higher TEG maximum amplitudes (MA), but by D14 LP was similar to FFP.

CONCLUSION

Despite significant declines in some factors in D40 LP, fibrinogen concentration and TEG MA were stable suggesting stored LP provides fibrinogen similarly to frozen plasmas even at D40. LP is easier to store and prepare for prehospital transfusion, important benefits when the alternative is crystalloid.

Whole Blood, Fixed Ratio, or Goal-Directed Blood Component Therapy for the Initial Resuscitation of Severely Hemorrhaging Trauma Patients: A Narrative Review

This narrative review explores the pathophysiology, geographic variation, and historical developments underlying the selection of fixed ratio versus whole blood resuscitation for hemorrhaging trauma patients. We also detail a physiologically driven and goal-directed alternative to fixed ratio and whole blood, whereby viscoelastic testing guides the administration of blood components and factor concentrates to the severely bleeding trauma patient. The major studies of each resuscitation method are highlighted, and upcoming comparative trials are detailed.

The use of whole blood in traumatic bleeding: a systematic review

Hemostatic resuscitation is currently considered a standard of care for the management of life-threatening hemorrhage, but in some critical settings the access to high quantities of blood components is problematic. Whole blood (WB) transfusion has been proposed as an alternative modality for hemostatic resuscitation of traumatic major bleeding. To assess the efficacy and safety of WB in trauma-associated massive bleeding, we performed a systematic review of the literature. We selected studies comparing WB transfusions to transfusion of blood components (COMP) in massive trauma bleeding; both randomized clinical trial (RCT) and observational studies were considered. The outcomes were mortality (30-day/in-hospital and 24-h mortality) and adverse events/transfusion reactions. The effect sizes were crude odds ratio (OR), adjusted OR and hazard ratio (HR). The methodological quality of studies was assessed using the Cochrane Risk of Bias tool for RCTs, and the ROBIN-1 tool for observational studies. The overall quality of the available evidence was assessed with the GRADE system. One RCT (2 reports) and 6 cohort studies were included (3642 adult patients; 675 receiving WB, 2967 receiving COMP). Three studies were conducted in military setting, and 4 in civilian setting. In the overall analysis, 30-day/in-hospital and 24-h mortality did not differ significantly between groups (very low quality of the evidence due to high risk of bias, imprecision and inconsistency). After adjustment for baseline covariates in three cohort studies, the OR for mortality was significantly lower in WB recipients compared to COMP (OR 0.22; 95% CIs 0.10/0.45) (moderate grade of evidence). Adverse events and transfusion reactions were overlooked and not consistently reported. The available evidence does not allow to draw definite conclusions on the short-term and long-term efficacy and safety of WB transfusion compared to COMP transfusion. Further well designed research is needed.

Low titer group O whole blood resuscitation: Military experience from the point of injury

INTRODUCTION

In the far forward combat environment, the use of whole blood is recommended for the treatment of hemorrhagic shock after injury. In 2016, US military special operations teams began receiving low titer group O whole blood (LTOWB) for use at the point of injury (POI). This is a case series of the initial 15 patients who received LTOWB on the battlefield.

METHODS

Patients were identified in the Department of Defense Trauma Registry, and charts were abstracted for age, sex, nationality, mechanism of injury, injuries and physiologic criteria that triggered the transfusion, treatments at the POI, blood products received at the POI and the damage-control procedures done by the first surgical team, next level of care, initial interventions by the second surgical team, Injury Severity Score, and 30-day survival. Descriptive statistics were used to characterize the clinical data when appropriate.

RESULTS

Of the 15 casualties, the mean age was 28, 50% were US military, and 63% were gunshot wounds. Thirteen patients survived to discharge, one died of wounds after arrival at the initial resuscitative surgical care, and two died prehospital. The mean Injury Severity Score was 21.31 (SD, 18.93). Eleven (68%) of the causalities received additional blood products during evacuation/role 2 and/or role 3. Vital signs were available for 10 patients from the prehospital setting and 9 patients upon arrival at the first surgical capable facility. The mean systolic blood pressure was 80.5 prehospital and 117 mm Hg (p = 0.0002) at the first surgical facility. The mean heart rate was 105 beats per minute prehospital and 87.4 beats per minute (p = 0.075) at the first surgical facility. The mean hospital stay was 24 days.

CONCLUSION

The use of cold-stored LTOWB at POI is feasible during combat operations. Further data are needed to validate and inform best practice for POI transfusion.

LEVEL OF EVIDENCE

Therapeutic study, level V.

Single Institution Trial Comparing Whole Blood vs Balanced Component Therapy: 50 Years Later

BACKGROUND

Early close ratio transfusion with balanced component therapy (BCT) has been associated with improved outcomes in patients with severe hemorrhage; however, this modality is not comparable with whole blood (WB) constituents. We compared use of BCT vs WB to determine if one yielded superior outcomes in patients with severe hemorrhage. We hypothesized that WB would lead to reduced in-hospital mortality and blood product volume if given in the first 24 hours of admission.

STUDY DESIGN

This was a 1-year, single institution, prospective, observational study comparing BCT with WB in adult (18+y) trauma patients with active hemorrhage who required blood transfusion upon arrival at the emergency department. Primary endpoint was in-hospital mortality. Secondary endpoints included 24-hour transfusion volumes, in-hospital clinical outcomes, and complications.

RESULTS

A total of 253 patients were included; 71.1% received BCT and 29.9% WB. The WB cohort had significantly more penetrating trauma (64.4% vs 48.9%; p = 0.03) and higher Shock Index (1.12 vs 0.92; p = 0.04). WB patients received significantly fewer units of packed red blood cells (PRBCs) (p < 0.001) and fresh frozen plasma (FFP) (p = 0.04), with a lower incidence of ARDS (p = 0.03) and fewer ventilator days (p = 0.03). Kaplan Meier survival analysis revealed no difference in survival between the 2 transfusion strategies (p = 0.80). When adjusted for various markers of injury severity and critical illness in Cox regression analysis, WB remained unassociated with mortality (hazard ratio 1.25; 95% CI 0.60-2.58; p = 0.55).

CONCLUSIONS

There was no difference in survival rates when comparing BCT with WB. In the WB group, the incidence of ARDS, duration of mechanical ventilation, massive transfusion protocol (MTP) activation, and transfusion volumes were significantly reduced. Further research should be directed at analyzing whether there is a true hemorrhage-related pathophysiologic benefit of WB when compared with BCT.

Effects of Blood Components and Whole Blood in a Model of Severe Trauma-Induced Coagulopathy

BACKGROUND

Plasma resuscitation ameliorates hyperfibrinolysis (HF) and trauma-induced coagulopathy (TIC). However, the use of other blood components to reduce HF has not been evaluated. Therefore, our aim was to determine the effect of individual blood components and whole blood (WB) on an in vitro model of severe HF/TIC.

METHODS

A "TIC" solution was made with 1:1 dilution of WB with saline and exacerbated with tissue plasminogen activator (tPA). Components were added in proportions equivalent to the thromboelastography (TEG) based goal-directed resuscitation used at our institution. Whole blood was added at proportions equal to what has been transfused in injured patients. Samples (n = 9) underwent citrated native and tPA-challenge (75 ng/mL) TEG with analysis of R-time, angle, MA, and LY30. Statistical analyses were completed employing the nonparametric Kruskal-Wallis and Dunn's multiple comparisons tests.

RESULTS

TIC solution, when compared to control, had a decrease in clot strength (MA 41 mm versus 51.5 mm, P < 0.01). The addition of tPA resulted in a severe coagulopathy (MA 24.5 mm versus 41 mm and LY30 52.8% versus 2.4%, P < 0.03 for all). The addition of 4U of WB improved clot strength compared to TIC + tPA (P = 0.03). No individual blood component resulted in improved fibrinolysis (P > 0.7). Cryoprecipitate improved R-time (7.5 versus 11.9 min, P < 0.01), angle (56.8 versus 30.2°) and MA (49 mm versus 36.25 mm), while platelets improved MA (44 mm versus 36.25 mm) compared to TIC + tPA (P < 0.03 for all).

CONCLUSIONS

No single blood component or volume of whole blood led to attenuation of tPA-mediated fibrinolysis in an in vitro model of TIC. Cryoprecipitate was the most effective at improving coagulation function.

Platelet transfusion: The effects of a fluid warmer on platelet function

Platelet (PLT) transfusions are an important component of hemostatic resuscitation. The AABB has published several guidelines recommending that PLT units should not be infused through blood warming devices.

STUDY DESIGN AND METHODS

Thirty-one units of hospital blood bank apheresis PLTs were obtained. PLT-rich plasma (PRP) aggregometry and thromboelastography (TEG) were performed on the unit samples before and after the units were infused through a Ranger blood/fluid warming device.

RESULTS

There were no differences in any of the aggregometry results before and after infusion of the PLTs through the blood warmer (all P > .32). There was a significant reduction in the TEG maximum amplitude (MA) of 69.8 ± 7.9 mm before and 66.0 ± 8.8 mm after (P < .001) infusion of the PLTs through the blood warmer and α angle 61.8 ± 9.4° before and 59.3 ± 8.2° after (P = .044) infusion of the PLTs through the blood warmer, although both mean values were within normal range for the TEG and not clinically significant. There were very good correlations of aggregometry and TEG results before and after infusion of the PLTs through the blood warmer device.

CONCLUSION

This study did not demonstrate significant deleterious effect on PLT function from infusing apheresis PLT units through a blood warming device by PRP aggregometry. We did detect a statistically significant-but not clinically significant-reduction in TEG MA and α angle. The prohibition of transfusing PLT units though the Ranger blood warming device is not indicated.

Emergency-release blood transfusions after postpartum hemorrhage at the Intermountain Healthcare hospitals

BACKGROUND

Most low-risk obstetric patients do not have crossmatched blood available to treat unexpected postpartum hemorrhage. An emergency-release blood transfusion (ERBT) program is critical for hospitals with obstetrical services. We performed a retrospective analysis of obstetrical ERBTs administered in our multihospital system.

DESIGN AND METHODS

We collected data from the past 8 years at all Intermountain Healthcare hospitals on every ERBT after postpartum hemorrhage; logging circumstances, number and type of transfused products, and outcomes.

RESULTS

Eighty-nine women received ERBT following 224,035 live births, for an incidence of 3.97 transfused women/10,000 births. The most common causally-associated conditions were: uterine atony (40%), placental abruption/placenta previa (16%), retained placenta (11%), and uterine rupture (5%). The mean number of total units transfused was 7.9 (range 1-76). The mean number of red blood cells (RBCs) transfused was 4.8, the median 4, and SD was ±4.4. Massive transfusion protocols (MTPs) for trauma recommend using a ratio of 1:1:1 or 2:1:1 of RBC:FFP:Platelets, however the ratios varied widely for postpartum hemorrhage. Only 1.5% received a 1:1:1 ratio and 7.5% received a 2:1:1 ratio. Nineteen percent (17/89) of women underwent hysterectomy, 7% (6/89) had uterine artery embolization, 36% (32/89) had an intensive care unit admission, and 1% (1/89) died.

CONCLUSION

Emergency transfusion for postpartum hemorrhage occurred after 1/2500 births. Most women received less FFP and platelets than recommended for traumatic hemorrhage. A potentially better practice for postpartum hemorrhage would be a balanced ratio of blood products, transfusion of low-titer, group O, cold-stored, whole blood, or inclusion in a MTP.

Whole blood for postpartum hemorrhage: early experience at two institutions

BACKGROUND

Death from postpartum hemorrhage (PPH) remains a significant preventable problem worldwide. Cold-stored, low-titer, type-O whole blood (LTOWB) is increasingly being used for resuscitation of injured patients, but it is uncommon in PPH patients, and it is unclear what its role may be in this population.

STUDY DESIGN AND METHODS

Brief report of the early experience of WB use for PPH in two institutions, one university hospital and one private hospital.

RESULTS

Different approaches have been implemented at the two institutions, one designed for emergency release, uncrossmatched transfusion of LTOWB as part of a massive transfusion protocol (MTP) and one for high-risk obstetric patients with known placental abnormalities. A total of 7 PPH patients have received a total of 17 units of LTOWB between the two institutions. No severe adverse transfusion reactions were observed clinically in either institution and the clinical outcomes were favorable in all cases.

CONCLUSION

In our early experience, LTOWB can be implemented for two different PPH clinical scenarios. Larger studies are needed to compare outcomes between LTOWB and traditional component resuscitation strategies.

Fresh Frozen Plasma-to-Packed Red Blood Cell Ratio and Mortality in Traumatic Hemorrhage: Nationwide Analysis of 4,427 Patients

BACKGROUND

Despite the presence of highly reliable data, studies on packed red blood cells (pRBC):fresh frozen plasma (FFP) ratio suffer from limited sample size and the presence of survivor bias. We sought to study the association between FFP:pRBC and early mortality in the hemorrhaging trauma patient.

STUDY DESIGN

This was a retrospective nationwide cohort that included all TQIP participating hospitals (2013 to 2016). We included all trauma patients who were transfused ≥10 pRBCs and ≥1 FFP within 24 hours. We excluded transferred patients and those who died in the emergency department or had missing/inaccurate transfusion data. Patients were assigned to 7 FFP:pRBC cohorts (range 1:1 to 1:6, and 1:6+) only if the ratio was similar at 4 and 24 hours and, to avoid survival bias, were excluded otherwise. Multivariable analyses correcting for all available confounders (age, demographics, comorbidities, vital signs, Injury Severity Score [ISS] and mechanism, procedures performed) were derived to study the independent relationship between FFP:pRBC and 24-hour mortality.

RESULTS

Of 1,002,595 patients, 4,427 patients were included. Mean age was 41 years, 79% were males, 61% had blunt trauma, and median ISS was 29. Most patients were transfused in a 1:1, 1:2, or 1:3 ratio (31%, 41%, and 11%, respectively); mortality ranged between 28% for 1:1 and 62% for 1:4. In multivariable analyses, the odds of mortality independently and incrementally increased to 1.23 (95% CI 1.02 to 1.48) for a 1:2 ratio, 2.11 (95% CI 1.42 to 3.13) for 1:4, and as high as 4.11 (95% CI 2.31 to 7.31) for 1:5 (all p < 0.05).

CONCLUSIONS

A 1:1 FFP:pRBC ratio is associated with the lowest mortality in the hemorrhaging trauma patient, and mortality increases with decreasing ratios.

Evaluating emergency-release blood transfusion of newborn infants at the Intermountain Healthcare hospitals

BACKGROUND

An emergency-release blood transfusion (ERBT) protocol (uncrossmatched type O-negative red blood cells, AB plasma, AB platelets) is critical for neonatology practice. However, few reports of emergency transfusions are available. We conducted an ERBT quality improvement project as a basis for progress.

STUDY DESIGN AND METHODS

For each ERBT in the past 8 years, we logged indications, products, locations and timing of the transfusions, and outcomes.

RESULTS

One hundred forty-nine ERBTs were administered; 42% involved a single blood product, and 58% involved two or more. The incidence was 6.25 ERBT per 10,000 live births, with a higher rate (9.52 ERBT/10,000) in hospitals with a Level 3 neonatal intensive care unit (NICU) (p < 0.001). Seventy percent of ERBTs were administered in a NICU and 30% in a delivery room, operating room, or emergency department. Indications were abruption/previa (32.2%), congenital anemia (i.e., fetomaternal hemorrhage; 15.4%), umbilical cord accident (i.e., velamentous insertion; 15.0%), and bleeding/coagulopathy (12.8%). Fifty-eight percent of those with hemorrhage before birth did not have a hemoglobin value reported on the umbilical cord gas; thus, anemia was not recognized initially. None of the 149 ERBTs were administered using a blood warmer. The mortality rate of recipients was 35%.

CONCLUSION

Based on our findings, we recommend including a hemoglobin value with every cord blood gas after emergency delivery to rapidly identify fetal anemia. We also discuss two potential improvements for future testing: 1) the use of a warming device for massive transfusion of neonates and 2) the use of low-titer group O cold-stored whole blood for massive hemorrhage in neonates.